Скачать или смотреть How to Update Specific Text in a File Using a Shell Script

Learn how to effortlessly update specific entries in a file using a shell script with user input in Linux.
---
This video is based on the question https://stackoverflow.com/q/76504401/ asked by the user 'Jordan Matthew Farmer' ( https://stackoverflow.com/u/7893296/ ) and on the answer https://stackoverflow.com/a/76504473/ provided by the user 'Freeman' ( https://stackoverflow.com/u/252518/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Update specific text in file from shell script

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Updating Specific Text in a File Using a Shell Script

Have you ever found yourself needing to update specific entries in a file? Whether it's configuration settings or environment variables, making changes manually can be tedious. Thankfully, shell scripting can help automate these processes, making them much more efficient. In this post, we'll explore how to update specific text in a document by prompting the user for input using a shell script.

The Challenge

Imagine you have a configuration file named .env that looks like this:

[[See Video to Reveal this Text or Code Snippet]]

You want to replace occurrences of yourdomain.com with a user-specified domain name on three different lines. How can you accomplish this using a shell script? Let’s dive into the solution!

Solution Overview

The solution involves using the sed command, a powerful stream editor for filtering and transforming text. The steps we'll follow are:

Prompt the user to enter their domain name.

Use sed to perform a search and replace operation on the .env file.

Display the updated values.

Step-By-Step Implementation

Let’s break down the script that accomplishes this task.

1. Prompting for User Input

First, we need to receive input from the user. We can do this using the read command in bash, which allows us to capture input in our variable called domain.

[[See Video to Reveal this Text or Code Snippet]]

2. Using sed for Text Replacement

Next, we utilize the sed command to find and replace occurrences of yourdomain.com with the value provided by the user. The command has the following syntax:

[[See Video to Reveal this Text or Code Snippet]]

-i: Edits the file in place.

s: Stands for ‘substitute’.

g: Global replacement (i.e., replace all occurrences on the line).

3. Outputting Updated Values

Finally, we can display the new values from the updated file to confirm the changes were successful. We do this using the cat command to print the contents of the .env file.

[[See Video to Reveal this Text or Code Snippet]]

Complete Script

Here is the full script, putting all the steps together:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Updating specific text in a configuration file can be made easy with a shell script using the sed command. By following the steps outlined in this guide, you can automate the process of modifying text entries based on user input, saving you both time and effort.

Remember, while I’ve provided a solution, the goal is to empower you to solve coding problems on your own. Happy scripting!